Novel diacylated hydrazines and process for the manufacture thereof



United States Patent NDVEL DIACYLATED HYDRAZINES AND PROCESS FOR THEMANUFACTURE THEREOF Balthasar Hegediis, Basel, Switzerland, assign-or toHottmann-La Roche line, Nntley, N. J., a corporation of New Jersey NoDrawing. Application November 3, 1953, Serial No. 390,095

Claims priority, application Switzerland December 2, 1952 11 Claims.(Cl. 2641-295) The present invention concerns novel diacylatedhydrazines of the general Formula (I) wherein (R) stands for the radicalof an a-amino acid, preferably having not more than about carbon atoms,from which the carboxylic and amino groups have been split otf, R1represents an acyl radical or a hydrogen atom, R2 a methyl group or ahydrogen atom and n is one of the numbers 1 and 2.

Suitable amino acids are for example methionine, a-al amine and thephenyl substituted derivatives thereof, glycine, leucine, lysine, etc.The symbol R1 may for example stand for the following acyl groups:acetyl, propionyl, butyryl, etc. or more particularly those acyl groups,

which may easily be hydrogenolyzed ofi' such as: the carbobenzoxy, thecarhoaliyloxy or the carbonaphthomethyloxy group.

The above compounds are crystallized substances, which are colorless orslightly yellow colored and which are easily to slightly soluble inwater, the reaction of the aqueous solution being neutral, if R1 is anacyl radical, or strongly alkaline, if R1 is a hydrogen atom. The saidcompounds are chemotherapeutically active, more particularly againsttuberculosis.

The invention further provides a process for the manufacture of theabove novel compounds which process comprises reacting a compound of thegeneral formula R'-NHNH2 with the anhydride or the acyl halide of anacid of the general formula R"OH, one of the two symbols R and R"representing the pyridyli-carb'onyl or the 2-methylepyridyl-4-carbonylradical, whereas the other symbol represents the acyl radical (NHRS)nwherein (R) stands for the radical of an a-amino acid, as defined above,from which the carboxylic and amino groups have been split off, R3 is anacyl radical and n is one of the numbers 1 and 2, whereupon, if R3 is acarbobenzoxy, carboallyloxy or carbonaphthomethyloxy radical, the lattergroup may be hydrogenolyzed ofi.

The invention also provides an alternative process for the manufactureof the same novel diacylated hydrazines of Formula I. This alternativeprocess comprises reacting a'mixed anhydride of the general formula(NHRsL.

obtained according to methods known per se from a N- acylated a-aminoacid, as defined above, and an acid halide of the general formulaHal'COR 1, with an acid "hydrazide of'the general formula R: whereupon,if R3 represents a carbobenzoxy, carboallyloxy or acarbonaphthomethyloxyradical, the said radical may be 'hydrogenolyzed off. 'In the aboveformulae ('R) stands "for 'the'radical of an w'amino acid, as definedabove, from acting the ester formed with hydrazine.

It will be understood that the present invention comprises the processdescribed as applied to all stereoisomeric forms of the amino acidsconcerned.

Example 1 61.5 .parts by weight of N-acetyl-methionine-hydrazide ofmelting point 100102 C. [prepared from N-acetylmethionine-ethyl-ester(Helvetica Chimica Acta, volume '12 (1929-), page 317) and hydrazinehydrate] are suspended in 360 parts by volume of anhydrous pyridine and,

with temporary cooling, 53.4 parts by weight of isonicotinic acidchloride hydrochloride are added portionwise. A clear, dark red-brownsolution is obtained. After allowing the same to stand overnight at roomtemperature, it is diluted with approx. 500 parts of Water, and 50 partsby weight of potassiumcarbonate are slowly added. The mixture isdistilled .in vacuo until the odor of .pyridine has disappeared, waterbeing repeatedly added, if need be. It is then diluted to 5004500 partsby volume, filtered through charcoal and the pH is adjusted to 4.55 bymeans of hydrochloric acid. After having beenmaintained for prolongedtime in an ice box, the N -isonicotinyl N -(N- acetyl-methionyl)hydrazine slowly begins to crystallize. After '23 days it is sucked offand recrystallized from little water. Melting point 203-204" C.

Example 2 .70 parts by weight of N-acetyl-leucine-hydrazide of meltingpoint 1Q0 C. [prepared from N-acetyl-leu- .cine-ethylester (HelveticaChimica Acta, volume 12 [1.929] page 3-17) and hydrazine hydrate] aresuspended in 300 parts by volume of anhydrous pyridine and, withtemporary cooling, 67 parts by weight of isonicotinic acid chloridehydrochloride are added. The red-brown solution is allowed to stand atroom temperature for 3 days and the reaction product is isolatedaccording to Example 1. The N -isonicotinyl-N-(N-acetyl-leucyl)hydrazine obtained is recrystallized from little waterand melts at 208-210" C.

Example 3 '18 parts by Weight of Neacetylphenylalanine-hydra zide (J.(Am. Chem. Soc., volume 72 [1950], page 5317) in 1.20 parts by volume ofpyridine are reacted with 14.5 parts by weight of isonicotinic'acidchloride hydrochloride as described in Examples 1 and 2. The reactionmixture is worked up as in Example 1. The N -isonicotinyl-N(N-acetyl-phenyl-alanyl)hydrazine formed is recrystallized in a largeamount of water and melts then at 210- 213 C.

enemas Example 4 29 parts by weight of N-acetyl-glycine-hydrazide ofmelting point 95-97" C. [prepared from N-acetyl-glycine-ethylester(Helvetica Chimica Acta, volume 12 [1929], page 317) and hydrazinehydrate] are suspended in 300 parts by volume of anhydrous pyridine and,while cooling, 54 parts by weight of isonicotinic acid chloridehydrochloride are added. The clear, brown-red solution is allowed tostand overnight at room temperature, then it is diluted with 1000 partsof water and 75 parts by weight of potassium carbonate are slowly added.The pyridine is removed by distillation in vacuo (smell control!) andthe solution is adjusted to pH 4.5-5 by means of hydrochloric acid.After one hours cooling with ice water, a small amount of precipitatedisonicotinic acid is removed by filtration, the filtrate is treated withcharcoal and filtered. The filtrate is evaporated in vacuo to a mash and1000 parts by volume of alcohol are added. The precipitated potassiumchloride is removed by sucking off, the

filtrate is evaporated in vacuo to dryness and the residue is completelydried by distilling twice in vacuo with 400 parts by volume of benzeneeach. The residue is boiled with 800 parts by volume of absolutealcohol, it is filtered from small amounts of potassium chloride andallowed to crystallize overnight in the ice box. After repeatedrecrystallization from 800 parts by volume of absolute alcohol, pure Nisonicotinyl-N -(N-acetyl-glycyl)-hydrazine is obtained. Melting point226-227 C.

Example 5 30 parts by weight of N-acetyl methionine-hydrazide (seeExample 1) are suspended in 180 parts by volume of anhydrous pyridineand, while cooling temporarily, 30 parts by weight ofZ-methyl-isonicotinic acid chloride hydrochloride are added portionwise.The mixture is allowed to stand overnight and processed further asdescribed in Example 1. The N -(2-methyl-isonicotinyl)- N-(N-acetyl-methionyl)-hydrazine obtained melts at 156-158 C.

Example 6 31.3 parts by weight ofN-carbobenzoxy-phenyl-alanine-hydrazide (Biochem. Journal, volume 46[1950], page 196) are suspended in 300 parts by volume of anhydrouspyridine and, while cooling temporarily, 17.8 parts by weight ofisonicotinic acid chloride hydrochloride are added. The mixture isworked up as described in Example 1. The N -isonicotinyl-N-(N-carbobenzoxy-phenyl-alanyl)-hydrazine formed is recrystallized from500-600 parts by volume of acetone. Melting point 183-185 C.

A solution of 30 parts by weight of N -isonicotinyl-N(N-carbobenzoxy-phenyl-alanyl) hydrazine in 300 parts by volume ofdioxane, 150 parts by weight of alcohol and 150 parts of water isenergetically stirred in the presence of palladium black, whileintroducing hydrogen. The hydrogenolysis is completed within -24 hours.The catalyst is filtered ofi, the solution is evaporated in vacuo andthe oily base is dissolved in little absolute alcohol. By the additionof alcoholic hydrochloric acid, the dihydrochloride of the N-isonicotinyl-N -phenyl-alany1-hydrazine is precipitated in the form ofwell-structured crystals. Melting point 235-237" C.

Example 7 10.3 parts by weight of acetyl-glycine-hydrazide are suspendedin 200 parts by volume of anhydrous pyridine and, while cooling, 19parts by weight of Z-methyl-isonicotinic acid chloride hydrochloride areadded. The mixture is worked up as described in Example 4. The N-(Z-methyl-isonicotiuyl)-N -acetyl-glycyl-hydrazine obtained melts at193194 C.

Example 8 19 parts by weight of hippuric acid hydrazide are suspended in200 parts by volume of anhydrous pyridine and,

while cooling, 17.6 parts by weight of isonicotinic acid chloridehydrochloride are added portionwise. The mixture is allowed to standovernight at room temperature, sucked off from small amounts ofinsoluble material and worked up as described in Example 1. The N-isonic0- tinyl-N -hippuryl-hydrazine melts at 240-242 C.

Example 9 As described in Example 8, 19 parts by weight of hippuric acidhydrazide are reacted with 19 parts by weight of Z-methyl-isonicotinicacid chloride hydrochloride. When working up in accordance with Example8, N -(2-methylisonicotinyl) -N -hippuryl-hydrazine of melting point224- 226 C. is obtained.

Example 1 0 14.5 parts 'by weight of DL-a-acetyl-alanine-hydrazide ofmelting point -136 C. (prepared from DL-a-acetylalanine-ethylester andhydrazine hydrate) are suspended in parts by volume of anhydrouspyridine and, as described in the preceding examples, reacted with 17.8parts by weight of isonicotinic acid chloride hydrochloride. Whenworking up in accordance with Example 1, the N -isonicotinyl-N-(DL-a-acetyl-alauyl) hydrazine obtained melts at 191-193 C.

Example 11 14.5 parts by weight of L(+)-oc-acetyl-alanine-hydrazide(melting point 137-139 C.; [a] =61 (0:1 in water), prepared fromL({)-u-acetyl-alanine-ethylester and hydrazine hydrate) are reacted, asdescribed in Example 10, with 17.8 parts by weight of isonicotinic acidchloride hydrochloride. The N -isonicotinyl-N-(L(+)-uacetyl-alanyl)-hydrazine obtained melts at 205-208 C.; [a]=-82.9 (c=1 in water).

Example 12 Example 13 14.5 parts by weight ofD()-u-acetyl-alamine-hydrazide (melting point 143-145 C.; [a] =+63.2(e=l in Water), prepared from D()-a-acetyl-alanine-ethylester andhydrazine hydrate) are reacted, as described in Example 10, with 17.8parts by weight of isonicotinic acid chloride hydrochloride. The N-isonicotinyl-N -(D()- a-acetyl-alanyl)-hydrazine obtained melts at204-205 C.; [al ={-83.8 (0:1 in Water).

Example 14 42 parts by weight of D(+)-acetyl-methionine-hydrazide(melting point 113-116 C.; [a] =+22.7 (c=1 in water), prepared fromD(+)-acetyl-methionine-ethylester and hydrazine hydrate) are reacted in200 parts by volume of anhydrous pyridine with 36.5 parts by weight ofisonicotinic acid chloride hydrochloride. The N -isonicotinyl-N-(D(+)-acetylmethionyl)-hydrazine is isolated in accordance with Example1 and melts at 186- 189 C.; lal =+39 (c=l iu N-hydrochloric acid).

Example 15 40 parts by weight of L(-)-acetyl-leucine-hydrazide (meltingpoint 135-137 (3.; [a] =37.5 (0:1 in water), prepared from L()-acetyl-leucine-ethylester and hydrazine hydrate) are reacted in 150parts by volume of anhydrous pyridine with 39 parts by weight of isonicotinic acid chloride hydrochloride. When working up as described inExample 2, the N -isonicotinyl-N -(L()- i s acetyl-leucyl)-hydrazinemelts at 222-225 C. 58.6 (:1 in N-hydr-ochloric acid).

Example 16 In a manner analogous to that of Example 15, 50 parts byweight of D(l)-acetyl-leucine-hydrazide (melting point 138-140 C.; [u]=|35.7 (0:1 in water) are reacted with 49 parts by weight ofisonicotinic acid chloride hydrochloride in 150 parts by volume ofanhydrous pyridine. The N -isonicotinyl-N -(D(+)-acetyl-leucyl)-hydrazine obtained melts at 222-227 C.; [a] =+60.8 (0:1 inN-hydrochloric acid).

Example 17 29 parts by weight of DL-acetyl-methionine are suspended in250 parts by volume of acetyl chloride. 32 parts by weight ofphosphorous pentachloride are added in 4-5 portions, while cooling withice and stirring. After two hours stirring, a clear solution isobtained, which for purposes of crystallization, is kept in an ice boxin the absence of humidity. The crystallized DL-acetykmet'h-.ionyl-chloride is sucked off after 18-20 hours and washed withpetroleum ether. Mel-ting point 91-94 C.

To a suspension of 2.7 parts by weight of isonicotinic acid hydrazide in60 parts by volume of absolute pyridine are added, while cooling, 4.2parts by weight of DL-acetylmethionyl-chloride. The mixture is worked upas in Example 1. The N -isonicotinyl-N -(DL-acetyl-methionyl)-hydrazineobtained melts at 203204 C. and, when mixed with the compound preparedin accordance with Example 1, no melting point depression is observed.

Example 18 19 parts by weight of N-acetyl-methionine are suspended in200 parts by volume of chloroform, and 11.2 parts by volume oftriethylamine are added thereto. The clear solution obtained is gettingwarm. It is cooled in ice water and, while stirring, 9.6 parts by volumeof ethyl chloro-formate diluted with little chloroform are added in thecourse of 10-15 minutes. During this operation, atmospheric moisturemust carefully be excluded. A mixed anhydride of N-acetylmethionine andmonoethyl carbonate is formed. After further 10 minutes, 13.6 parts byweight of isonicotinic acid hydrazide are added and the mixture isstirred without cooling for 2 hours. It is then shaken with 400 parts byvolume of 1.5 N hydrochloric acid, the aqueous layer is washed once withether, the other is removed in vacuo and the reaction of the solution isadjusted to pH 5 by means of sodium hydroxide solution. The N-isonicotinyl-N -(N-acetyl-methionyl)-hydrazine crystallizes overnightin the ice box. After recrystallization from water it melts at 203-204C.

Example 19 When working according to Example 18, except that 15 parts byweight of 2-methyl-pyridine-4-carboxylic acid hydrazide are used insteadof isonicotinic acid hydrazide, the product obtained is N-(2-methyl-pyridyl-4-carbonyl)- N -(N-acetyl-methionyl)-hydrazine, whichafter recrystallization from Water melts at 156-15 8 C.

Example 20 32 parts by weight of N-carbobenzoxy-glycine are dissolvedtogether with 16.8 parts by volume of triethylamine in 300 parts byvolume of chloroform and, as described in Example 18, reacted with 14.4parts by volume of ethyl chloro-formate. The mixed anhydride ofN-carbobenzoxy-glycine and monoethyl carbonate is formed. After 10minutes, 20.4 parts by weight of isonicotinic acid hydrazide are addedand the mixture is worked up as described in Example 18. Afterrecrystallization from much water, the N -isonicotinyl-N-(N-carbobenzoxyglycyl)-hydrazine obtained melts at 159-160 C.

30 parts by weight of the above compound are dissolved in a mixture of600 parts by volume of water and parts by volume of concentratedhydrochloric acid.

After addition of 0.1-0.2 part by weight of palladium black, hydrogen isintroduced with energetic stirring during 20-24 hours. The solution isfiltered off from the catalyst and concentrated in vacuo. It is thenadjusted to pH 7.8-8 by means of aqueous sodium hydroxide, whereupon theN -isonicotinyl-N -glycyl-hydrazine soon begins to precipitate. Afterrecrystallization from water, it melts at 212-214 C.

Example 21 When working according to Example 20, except that 33.4 partsby weight of N-carbobenzoxy-a-alanine are used instead ofN-carbobenzoxy-glycine, the product obtained is N -isonicotinyl-N-(N-carbobenzoxy-a-alanyl)- hydrazine, which after recrystallizationfrom much water melts at 192-194 C. Upon hydrogenolysis in accordancewith the procedure of Example 20, the above product is converted into N-isonicotinyl-N -(a-alanyl)hydi'azine, which after recrystallization inlittle water melts at l99-200 C.

Example 22 When proceeding according to Example 20, except that 26 partsby weight of L(+)-N-carbobenzoxy-rat-alanine are used instead ofN-carbobenzoxy-glycine, and, once the hydrogenolysis is completed,concentrating in vacuo and precipitating with alcohol, the productobtained is (-1-) N -isonicotinyl-N -(L-a-alanyl)-hydrazine-dihydrochloride, which melts at 230-234 C.; [u] =24.8 (c=1 inwater).

Example 23 When proceeding according to Example 20, except that 60 partsby weight of DL-N-carbobenzoxy-leucine are used instead ofN-carbobenzoxy-glycine and, once the hydrogenolysis is completed,concentrating in vacuo, dissolving the residue in alcohol andprecipitating with ethyl acetate, the product obtained is N-isonicotinyl-N -(DL- leucyl)-hydrazine-dihydrochloride, which melts at220- 224 C.

Example 24 wherein R represents the radical of a naturally occurringa-amino acid, having less than 11 carbon atoms, from which the carboxygroup and the amino group have been split off, R1 represents a member ofthe group consisting of hydrogen, acyl, carbalkoxy and carbaralkoxy, R2represents a member of the group consisting of hydrogen and methyl, andn represents an integer from 1 t0 2, which comprises reacting a memberof the group consisting of isonicotinic acid hydrazide and 2-methylisonicotinic acid hydrazide with a member of the group consisting of theanhydride and acyl halide of an acid having the formula "-OH wherein R"represents the acyl radical R, R1 and n having the same significance asabove.

2. A process for the production of diacylated hydrazines .WhlChcomprises reacting a mixed anhydride represented by the formula whereinR represents the radical of a naturally occurring OLramlIlO acid, havingless than 11 carbon atoms, from which the carboxy and amino groups havebeen split off, R3 represents a member of the group consisting of acyl,carbalkoxy and carbaralkoxy, R4 is a member of the group consisting ofalkoxy, aryl and alkyl, and n represents an integer from 1 to 2, with anacid hydrazide represented by the formula wherein R2 represents a memberof the group consisting of hydrogen and methyl.

3. Process in accordance with claim 2, which comprises reactingisonicotinic acid hydrazide with the mixed anhydride obtained fromN-acetyl-methionine and ethyl chloro-formate.

4. Process in accordance with claim 2, which comprises reacting2-methyl-pyridine-4-carboxylic acid hydrazide with the mixed anhydrideobtained from N-acetyl-methionine and ethyl chloroformate.

5. A diacylated hydrazine represented by the formula wherein Rrepresents the radical of a naturally occurring a-amino acid, havingless than 11 carbon atoms, from which the carboxy group and the aminogroup have been split off, R1 presents a member of the group consistingof hydrogen, acyl, carbalkoxy and carbaralkoxy, R2 represents a memberof the group consisting of hydrogen and methyl, and n represents aninteger from 1 to 2.

6. N isonicotinyl-N -(N-acetyl-methionyl) hydrazine.

7. A N isonicotinyl N (a-amino-acyl)-hydrazine, wherein the amino-acylradical is a radical of a naturally occurring u-amino acid having lessthan 11 carbon atoms.

8. A N -isonicotinyl-N -(or-acylamino-acyl)-hydrazine wherein theamino-acyl radical is a radical of a naturally occurring a-amino acidhaving less than 11 carbon atoms.

9. A N (2 rnethyl-isonicotinyl)-N -(a-amino-acyl)- hydrazine, whereinthe amino-acyl radical is a radical of a naturally occurring u-aminoacid having less than 11 carbon atoms.

10. A N (2 methyl isonicotinyl)-N -(a-acylaminoacyl)-hydrazine, whereinthe arnino-acyl radical is a radical of a naturally occurring Ol-amlHOacid having less than 11 carbon atoms.

11. N (2 methyl-isonicotinyl) -N -(N-acetyl-methi onyl) -hydrazine.

References Cited in the file of this patent Conant et al.: The Chem. orOreg. Compounds, 3rd ed., 1947.

5. A DIACYLATED HYDRAZINE REPRESENTED BY THE FORMULA